What Is Sunscreen? SPF 50 and UVA vs UVB | SLAM
The front of a sunscreen bottle can read like a tiny exam: SPF, UVA, UVB, broad spectrum, water resistant.
You do not need a chemistry degree to choose a bottle. You do need to know which words describe protection and which words do not buy you extra time outside.
What is sunscreen?
Sunscreen is a product applied to skin to help protect it from the sun's ultraviolet radiation. Its active ingredients absorb UV energy; mineral sunscreen ingredients also reflect some of it.
The FDA regulates sunscreen as an over-the-counter drug in the United States. That is why the Drug Facts label and application directions deserve more attention than a catchy name.
What does SPF 50 mean?
SPF stands for sun protection factor. It measures protection against sunburn under test conditions, primarily reflecting protection from UVB rays.
SPF 50 does not mean fifty hours of protection. It does not tell you to use less product or skip reapplication. The protection on the label depends on proper use, and no sunscreen blocks all UV radiation.
What is the difference between UVA and UVB?
Both are forms of ultraviolet radiation, and overexposure to either can contribute to skin cancer. UVA is associated with premature skin aging and can pass through window glass. UVB is the main cause of sunburn.
Think of this as a reason to read the whole label rather than judging protection only by whether you turn red.
What does broad spectrum mean?
Broad-spectrum sunscreen protects against both UVA and UVB rays. The SPF number alone is not the whole picture; look for "broad spectrum" on the label too.
For SLAM's Men's Cologne SPF Spray, the current product page identifies broad-spectrum SPF 50 protection. Check the label on the bottle you are using rather than assuming every bottle or format has identical directions.
Does water resistant mean waterproof?
No. No sunscreen is waterproof. A water-resistance claim states a tested time limit during swimming or sweating, not a promise of protection through an entire afternoon.
SLAM's Men's Cologne SPF Spray lists 80-minute water resistance. Its directions call for reapplication after 80 minutes of swimming or sweating, immediately after towel drying and at least every two hours.
Read the bottle in this order
First: broad spectrum and SPF. Next: water resistance and directions. Then: expiration date and storage instructions. Finally: whether the texture, format and fragrance suit you.
MysteryMan Sunscreen Lotion is labeled SPF 50 on the product tube shown here. Its lotion format lets you dispense and spread it by hand. If you prefer a spray dispenser, apply generously and rub it in.
A good label is the start. Using the product properly is the part you control.
FAQ
Is SPF a timer?
No. It is a sunburn-protection rating measured under test conditions, not a number of hours you can stay outdoors.
Can I still get sunburned wearing sunscreen?
Yes. No sunscreen blocks all UV rays, and too little product, missed patches or skipped reapplication reduce protection.
Does cologne scent add sun protection?
No. The active sunscreen ingredients provide protection. Fragrance is a separate preference.